The treasure of the lake

Yasir gives the children a poster of their family tree and asks them to take the baroness with her and hand her over. Unfortunately, Baby Joe drips some applesauce on it, directly onto the image of Sophie, the Baroness' oldest ancestor. The attempt of Miss Moon to wipe the muss only worsens the situation: she wipes the whole picture away. The result: the entire family branch of the Baroness disappears from the poster, including their house next door, as if it had never existed. How do they just bring their neighbor back?